VCAN communication bus - Bus off
'As precondition connected ECU shall not be offline. '- Measure the resistance (with the battery disconnected) between CAN-high and CAN-low at the Environment Sensor CAN bus. It should be close to 60 ohm (one 120 ohm termination resistor in each end of the CAN-bus). - Measure the resistance (with the battery disconnected) between CAN-high and supply. It should be high ohmic (Mega ohm). - Measure the resistance (with the battery disconnected) between CAN-high and ground. It should be high ohmic (Mega ohm). - Measure the resistance (with the battery disconnected) between CAN-low and supply. It should be high ohmic (Mega ohm). - Measure the resistance (with the battery disconnected) between CAN-low and ground. It should be high ohmic (Mega ohm). 'Disconnect one ECU unit at the time from the Environment Sensor CAN bus and check if the fault disappears. If problem persists change the cable harness.
What you'll see
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System reaction
Functions dependent on information from the Environment Sensor CAN bus are degraded, as tracker, kink angle and free space Sensor cannot receive or send CAN messages. Sensor will be degraded. Sensor target output will be error.
Diagnostic depth
The DTC is set active if there is a detected bus off at theEnvironment Sensor CAN bus. No set when voltage out of operating range. Validation time 0ms, and invalidation time 1000ms.
• Defect wiring of Environment Sensor CAN bus: - short circuit between CAN-high and CAN low. - short circuit between CAN-high and ground. - short circuit between CAN-low and supply voltage. • Defect ECU unit(s) on the Environment Sensor CAN bus.